summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2024-11-07futex: Switch to use hrtimer_setup_sleeper_on_stack()Nam Cao
hrtimer_setup_sleeper_on_stack() replaces hrtimer_init_sleeper_on_stack() to keep the naming convention consistent. Convert the usage site over to it. The conversion was done with Coccinelle. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/d92116a17313dee283ebc959869bea80fbf94cdb.1730386209.git.namcao@linutronix.de
2024-11-07fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()Nam Cao
hrtimer_setup_sleeper_on_stack() replaces hrtimer_init_sleeper_on_stack() to keep the naming convention consistent. Convert the usage site over to it. The conversion was done with Coccinelle. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/5f10c259fa43ba2fe774de5b2cedc22f5e9cfd2d.1730386209.git.namcao@linutronix.de
2024-11-07hrtimers: Introduce hrtimer_update_function()Nam Cao
Some users of hrtimer need to change the callback function after the initial setup. They write to hrtimer::function directly. That's not safe under all circumstances as the write is lockless and a concurrent timer expiry might end up using the wrong function pointer. Introduce hrtimer_update_function(), which also performs runtime checks whether it is safe to modify the callback. This allows to make hrtimer::function private once all users are converted. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20a937b0ae09ad54b5b6d86eabead7c570f1b72e.1730386209.git.namcao@linutronix.de
2024-11-07hrtimers: Introduce hrtimer_setup_sleeper_on_stack()Nam Cao
The hrtimer_init*() API is replaced by hrtimer_setup*() variants to initialize the timer including the callback function at once. hrtimer_init_sleeper_on_stack() does not need user to setup the callback function separately, so a new variant would not be strictly necessary. Nonetheless, to keep the naming convention consistent, introduce hrtimer_setup_sleeper_on_stack(). hrtimer_init_on_stack() will be removed once all users are converted. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/7b5e18e6dd0ace9eaa211201528cb9dc23752454.1730386209.git.namcao@linutronix.de
2024-11-07hrtimers: Introduce hrtimer_setup_on_stack()Nam Cao
To initialize hrtimer on stack, hrtimer_init_on_stack() needs to be called and also hrtimer::function must be set. This is error-prone and awkward to use. Introduce hrtimer_setup_on_stack() which does both of these things, so that users of hrtimer can be simplified. The new setup function also has a sanity check for the provided function pointer. If NULL, a warning is emitted and a dummy callback installed. hrtimer_init_on_stack() will be removed as soon as all of its users have been converted to the new function. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/4b05e2ab3a82c517adf67fabc0f0cd8fe118b97c.1730386209.git.namcao@linutronix.de
2024-11-07hrtimers: Introduce hrtimer_setup() to replace hrtimer_init()Nam Cao
To initialize hrtimer, hrtimer_init() needs to be called and also hrtimer::function must be set. This is error-prone and awkward to use. Introduce hrtimer_setup() which does both of these things, so that users of hrtimer can be simplified. The new setup function also has a sanity check for the provided function pointer. If NULL, a warning is emitted and a dummy callback installed. hrtimer_init() will be removed as soon as all of its users have been converted to the new function. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/5057c1ddbfd4b92033cd93d37fe38e6b069d5ba6.1730386209.git.namcao@linutronix.de
2024-11-07io_uring: Remove redundant hrtimer's callback function setupNam Cao
The IORING_OP_TIMEOUT command uses hrtimer underneath. The timer's callback function is setup in io_timeout(), and then the callback function is setup again when the timer is rearmed. Since the callback function is the same for both cases, the latter setup is redundant, therefore remove it. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jens Axboe <axboe@kernel.dk: Link: https://lore.kernel.org/all/07b28dfd5691478a2d250f379c8b90dd37f9bb9a.1730386209.git.namcao@linutronix.de
2024-11-07_RESEND_PATCH_v2_04_19_wifi_rt2x00_Remove_redundant_hrtimer_init_Nam Cao
rt2x00usb_probe() executes a hrtimer_init() for txstatus_timer. Afterwards, rt2x00lib_probe_dev() is called which also initializes this txstatus_timer with the same settings. Remove the redundant hrtimer_init() call in rt2x00usb_probe(). Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/all/66116057f788e18a6603d50a554417eee459e02c.1730386209.git.namcao@linutronix.de
2024-11-07KVM: x86/xen: Initialize hrtimer in kvm_xen_init_vcpu()Nam Cao
The hrtimer is initialized in the KVM_XEN_VCPU_SET_ATTR ioctl. That caused problem in the past, because the hrtimer can be initialized multiple times, which was fixed by commit af735db31285 ("KVM: x86/xen: Initialize Xen timer only once"). This commit avoids initializing the timer multiple times by checking the field 'function' of struct hrtimer to determine if it has already been initialized. This is not required and in the way to make the function field private. Move the hrtimer initialization into kvm_xen_init_vcpu() so that it will only be initialized once. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/all/9c33c7224d97d08f4fa30d3cc8687981c1d3e953.1730386209.git.namcao@linutronix.de
2024-11-07drm/i915/request: Remove unnecessary modification of hrtimer:: FunctionNam Cao
When a request is created, the hrtimer is not initialized and only its 'function' field is set to NULL. The hrtimer is only initialized when the request is enqueued. The point of setting 'function' to NULL is that, it can be used to check whether hrtimer_try_to_cancel() should be called while retiring the request. This "trick" is unnecessary, because hrtimer_try_to_cancel() already does its own check whether the timer is armed. If the timer is not armed, hrtimer_try_to_cancel() returns 0. Fully initialize the timer when the request is created, which allows to make the hrtimer::function field private once all users of hrtimer_init() are converted to hrtimer_setup(), which requires a valid callback function to be set. Because hrtimer_try_to_cancel() returns 0 if the timer is not armed, the logic to check whether to call i915_request_put() remains equivalent. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/50f865045aa672a9730343ad131543da332b1d8d.1730386209.git.namcao@linutronix.de
2024-11-07hrtimers: Add missing hrtimer_init() trace pointsNam Cao
hrtimer_init*_on_stack() is not covered by tracing when CONFIG_DEBUG_OBJECTS_TIMERS=y. Rework the functions similar to hrtimer_init() and hrtimer_init_sleeper() so that the hrtimer_init() tracepoint is unconditionally available. The rework makes hrtimer_init_sleeper() unused. Delete it. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/74528e8abf2bb96e8bee85ffacbf14e15cf89f0d.1730386209.git.namcao@linutronix.de
2024-11-07softirq: Use a dedicated thread for timer wakeups on PREEMPT_RT.Sebastian Andrzej Siewior
The timer and hrtimer soft interrupts are raised in hard interrupt context. With threaded interrupts force enabled or on PREEMPT_RT this leads to waking the ksoftirqd for the processing of the soft interrupt. ksoftirqd runs as SCHED_OTHER task which means it will compete with other tasks for CPU resources. This can introduce long delays for timer processing on heavy loaded systems and is not desired. Split the TIMER_SOFTIRQ and HRTIMER_SOFTIRQ processing into a dedicated timers thread and let it run at the lowest SCHED_FIFO priority. Wake-ups for RT tasks happen from hardirq context so only timer_list timers and hrtimers for "regular" tasks are processed here. The higher priority ensures that wakeups are performed before scheduling SCHED_OTHER tasks. Using a dedicated variable to store the pending softirq bits values ensure that the timer are not accidentally picked up by ksoftirqd and other threaded interrupts. It shouldn't be picked up by ksoftirqd since it runs at lower priority. However if ksoftirqd is already running while a timer fires, then ksoftird will be PI-boosted due to the BH-lock to ktimer's priority. The timer thread can pick up pending softirqs from ksoftirqd but only if the softirq load is high. It is not be desired that the picked up softirqs are processed at SCHED_FIFO priority under high softirq load but this can already happen by a PI-boost by a force-threaded interrupt. [ frederic@kernel.org: rcutorture.c fixes, storm fix by introduction of local_timers_pending() for tick_nohz_next_event() ] [ junxiao.chang@intel.com: Ensure ktimersd gets woken up even if a softirq is currently served. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> [rcutorture] Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241106150419.2593080-4-bigeasy@linutronix.de
2024-11-07timers: Use __raise_softirq_irqoff() to raise the softirq.Sebastian Andrzej Siewior
Raising the timer soft interrupt is always done from hard interrupt context, so it can be reduced to just setting the TIMER soft interrupt flag. The soft interrupt will be invoked on return from interrupt. Use therefore __raise_softirq_irqoff() to raise the TIMER soft interrupt, which is a trivial optimization. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241106150419.2593080-3-bigeasy@linutronix.de
2024-11-07hrtimer: Use __raise_softirq_irqoff() to raise the softirqSebastian Andrzej Siewior
Raising the hrtimer soft interrupt is always done from hard interrupt context, so it can be reduced to just setting the HRTIMER soft interrupt flag. The soft interrupt will be invoked on return from interrupt. Use therefore __raise_softirq_irqoff() to raise the HRTIMER soft interrupt, which is a trivial optimization. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241106150419.2593080-2-bigeasy@linutronix.de
2024-11-07alarmtimers: Remove return value from alarm functionsThomas Gleixner
Now that the SIG_IGN problem is solved in the core code, the alarmtimer callbacks do not require a return value anymore. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241105064214.318837272@linutronix.de
2024-11-07alarmtimers: Remove the throttle mechanism from alarm_forward_now()Thomas Gleixner
Now that ignored posix timer signals are requeued and the timers are rearmed on signal delivery the workaround to keep such timers alive and self rearm them is not longer required. Remove the unused alarm timer parts. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064214.252443020@linutronix.de
2024-11-07posix-timers: Cleanup SIG_IGN workaround leftoversThomas Gleixner
Now that ignored posix timer signals are requeued and the timers are rearmed on signal delivery the workaround to keep such timers alive and self rearm them is not longer required. Remove the relevant hacks and the not longer required return values from the related functions. The alarm timer workarounds will be cleaned up in a separate step. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064214.187239060@linutronix.de
2024-11-07signal: Queue ignored posixtimers on ignore listThomas Gleixner
Queue posixtimers which have their signal ignored on the ignored list: 1) When the timer fires and the signal has SIG_IGN set 2) When SIG_IGN is installed via sigaction() and a timer signal is already queued This only happens when the signal is for a valid timer, which delivered the signal in periodic mode. One-shot timer signals are correctly dropped. Due to the lock order constraints (sighand::siglock nests inside timer::lock) the signal code cannot access any of the timer fields which are relevant to make this decision, e.g. timer::it_status. This is addressed by establishing a protection scheme which requires to lock both locks on the timer side for modifying decision fields in the timer struct and therefore makes it possible for the signal delivery to evaluate with only sighand:siglock being held: 1) Move the NULLification of timer->it_signal into the sighand::siglock protected section of timer_delete() and check timer::it_signal in the code path which determines whether the signal is dropped or queued on the ignore list. This ensures that a deleted timer cannot be moved onto the ignore list, which would prevent it from being freed on exit() as it is not longer in the process' posix timer list. If the timer got moved to the ignored list before deletion then it is removed from the ignored list under sighand lock in timer_delete(). 2) Provide a new timer::it_sig_periodic flag, which gets set in the signal queue path with both timer and sighand locks held if the timer is actually in periodic mode at expiry time. The ignore list code checks this flag under sighand::siglock and drops the signal when it is not set. If it is set, then the signal is moved to the ignored list independent of the actual state of the timer. When the signal is un-ignored later then the signal is moved back to the signal queue. On signal delivery the posix timer side decides about dropping the signal if the timer was re-armed, dis-armed or deleted based on the signal sequence counter check. If the thread/process exits then not yet delivered signals are discarded which means the reference of the timer containing the sigqueue is dropped and frees the timer. This is way cheaper than requiring all code paths to lock sighand::siglock of the target thread/process on any modification of timer::it_status or going all the way and removing pending signals from the signal queues on every rearm, disarm or delete operation. So the protection scheme here is that on the timer side both timer::lock and sighand::siglock have to be held for modifying timer::it_signal timer::it_sig_periodic which means that on the signal side holding sighand::siglock is enough to evaluate these fields. In posixtimer_deliver_signal() holding timer::lock is sufficient to do the sequence validation against timer::it_signal_seq because a concurrent expiry is waiting on timer::lock to be released. This completes the SIG_IGN handling and such timers are not longer self rearmed which avoids pointless wakeups. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064214.120756416@linutronix.de
2024-11-07signal: Handle ignored signals in do_sigaction(action != SIG_IGN)Thomas Gleixner
When a real handler (including SIG_DFL) is installed for a signal, which had previously SIG_IGN set, then the list of ignored posix timers has to be checked for timers which are affected by this change. Add a list walk function which checks for the matching signal number and if found requeues the timers signal, so the timer is rearmed on signal delivery. Rearming the timer right away is not possible because that requires to drop sighand lock. No functional change as the counter part which queues the timers on the ignored list is still missing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064214.054091076@linutronix.de
2024-11-07posix-timers: Handle ignored list on delete and exitThomas Gleixner
To handle posix timer signals on sigaction(SIG_IGN) properly, the timers will be queued on a separate ignored list. Add the necessary cleanup code for timer_delete() and exit_itimers(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.987530588@linutronix.de
2024-11-07signal: Provide ignored_posix_timers listThomas Gleixner
To prepare for handling posix timer signals on sigaction(SIG_IGN) properly, add a list to task::signal. This list will be used to queue posix timers so their signal can be requeued when SIG_IGN is lifted later. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.920101900@linutronix.de
2024-11-07posix-timers: Move sequence logic into struct k_itimerThomas Gleixner
The posix timer signal handling uses siginfo::si_sys_private for handling the sequence counter check. That indirection is not longer required and the sequence count value at signal queueing time can be stored in struct k_itimer itself. This removes the requirement of treating siginfo::si_sys_private special as it's now always zero as the kernel does not touch it anymore. Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Link: https://lore.kernel.org/all/20241105064213.852619866@linutronix.de
2024-11-07signal: Cleanup unused posix-timer leftoversThomas Gleixner
Remove the leftovers of sigqueue preallocation as it's not longer used. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.786506636@linutronix.de
2024-11-07posix-timers: Embed sigqueue in struct k_itimerThomas Gleixner
To cure the SIG_IGN handling for posix interval timers, the preallocated sigqueue needs to be embedded into struct k_itimer to prevent life time races of all sorts. Now that the prerequisites are in place, embed the sigqueue into struct k_itimer and fixup the relevant usage sites. Aside of preparing for proper SIG_IGN handling, this spares an extra allocation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.719695194@linutronix.de
2024-11-07signal: Replace resched_timer logicThomas Gleixner
In preparation for handling ignored posix timer signals correctly and embedding the sigqueue struct into struct k_itimer, hand down a pointer to the sigqueue struct into posix_timer_deliver_signal() instead of just having a boolean flag. No functional change. Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Link: https://lore.kernel.org/all/20241105064213.652658158@linutronix.de
2024-11-07signal: Refactor send_sigqueue()Thomas Gleixner
To handle posix timers which have their signal ignored via SIG_IGN properly it is required to requeue a ignored signal for delivery when SIG_IGN is lifted so the timer gets rearmed. Split the required code out of send_sigqueue() so it can be reused in context of sigaction(). While at it rename send_sigqueue() to posixtimer_send_sigqueue() so its clear what this is about. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.586453412@linutronix.de
2024-11-07posix-timers: Store PID type in the timerThomas Gleixner
instead of re-evaluating the signal delivery mode everywhere. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.519086500@linutronix.de
2024-11-07signal: Provide posixtimer_sigqueue_init()Thomas Gleixner
To cure the SIG_IGN handling for posix interval timers, the preallocated sigqueue needs to be embedded into struct k_itimer to prevent life time races of all sorts. Provide a new function to initialize the embedded sigqueue to prepare for that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.450427515@linutronix.de
2024-11-07signal: Split up __sigqueue_alloc()Thomas Gleixner
To cure the SIG_IGN handling for posix interval timers, the preallocated sigqueue needs to be embedded into struct k_itimer to prevent life time races of all sorts. Reorganize __sigqueue_alloc() so the ucounts retrieval and the initialization can be used independently. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.371410037@linutronix.de
2024-11-07posix-timers: Add a refcount to struct k_itimerThomas Gleixner
To cure the SIG_IGN handling for posix interval timers, the preallocated sigqueue needs to be embedded into struct k_itimer to prevent life time races of all sorts. To make that work correctly it needs reference counting so that timer deletion does not free the timer prematuraly when there is a signal queued or delivered concurrently. Add a rcuref to the posix timer part. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.304756440@linutronix.de
2024-11-07posix-cpu-timers: Use dedicated flag for CPU timer nanosleepThomas Gleixner
POSIX CPU timer nanosleep creates a k_itimer on stack and uses the sigq pointer to detect the nanosleep case in the expiry function. Prepare for embedding sigqueue into struct k_itimer by using a dedicated flag for nanosleep. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.238550394@linutronix.de
2024-11-07posix-cpu-timers: Cleanup the firing logicThomas Gleixner
The firing flag of a posix CPU timer is tristate: 0: when the timer is not about to deliver a signal 1: when the timer has expired, but the signal has not been delivered yet -1: when the timer was queued for signal delivery and a rearm operation raced against it and supressed the signal delivery. This is a pointless exercise as this can be simply expressed with a boolean. Only if set, the signal is delivered. This makes delete and rearm consistent with the rest of the posix timers. Convert firing to bool and fixup the usage sites accordingly and add comments why the timer cannot be dequeued right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241105064213.172848618@linutronix.de
2024-11-07posix-timers: Make signal overrun accounting sensibleThomas Gleixner
The handling of the timer overrun in the signal code is inconsistent as it takes previous overruns into account. This is just wrong as after the reprogramming of a timer the overrun count starts over from a clean state, i.e. 0. Don't touch info::si_overrun in send_sigqueue() and only store the overrun value at signal delivery time, which is computed from the timer itself relative to the expiry time. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20241105064213.106738193@linutronix.de
2024-11-07posix-timers: Make signal delivery consistentThomas Gleixner
Signals of timers which are reprogammed, disarmed or deleted can deliver signals related to the past. The POSIX spec is blury about this: - "The effect of disarming or resetting a timer with pending expiration notifications is unspecified." - "The disposition of pending signals for the deleted timer is unspecified." In both cases it is reasonable to expect that pending signals are discarded. Especially in the reprogramming case it does not make sense to account for previous overruns or to deliver a signal for a timer which has been disarmed. This makes the behaviour consistent and understandable. Remove the si_sys_private check from the signal delivery code and invoke posix_timer_deliver_signal() unconditionally for posix timer related signals. Change posix_timer_deliver_signal() so it controls the actual signal delivery via the return value. It now instructs the signal code to drop the signal when: 1) The timer does not longer exist in the hash table 2) The timer signal_seq value is not the same as the si_sys_private value which was set when the signal was queued. This is also a preparatory change to embed the sigqueue into the k_itimer structure, which in turn allows to remove the si_sys_private magic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241105064213.040348644@linutronix.de
2024-11-07posix-cpu-timers: Correctly update timer status in posix_cpu_timer_del()Thomas Gleixner
If posix_cpu_timer_del() exits early due to task not found or sighand invalid, it fails to clear the state of the timer. That's harmless but inconsistent. These early exits are accounted as successful delete. Move the update of the timer state into the success return path, so all "successful" deletions are handled. Reported-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20241105064212.974053438@linutronix.de
2024-11-07btrfs: fix the length of reserved qgroup to freeHaisu Wang
The dealloc flag may be cleared and the extent won't reach the disk in cow_file_range when errors path. The reserved qgroup space is freed in commit 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range"). However, the length of untouched region to free needs to be adjusted with the correct remaining region size. Fixes: 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range") CC: stable@vger.kernel.org # 6.11+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Haisu Wang <haisuwang@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07btrfs: reinitialize delayed ref list after deleting it from the listFilipe Manana
At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead. Fixes: 1d57ee941692 ("btrfs: improve delayed refs iterations") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07btrfs: fix per-subvolume RO/RW flags with new mount APIQu Wenruo
[BUG] With util-linux 2.40.2, the 'mount' utility is already utilizing the new mount API. e.g: # strace mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test/ ... fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 But this leads to a new problem, that per-subvolume RO/RW mount no longer works, if the initial mount is RO: # mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test # mount -o rw,subvol=subv2 /dev/test/scratch1 /mnt/scratch # mount | grep mnt /dev/mapper/test-scratch1 on /mnt/test type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=256,subvol=/subv1) /dev/mapper/test-scratch1 on /mnt/scratch type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=257,subvol=/subv2) # touch /mnt/scratch/foobar touch: cannot touch '/mnt/scratch/foobar': Read-only file system This is a common use cases on distros. [CAUSE] We have a workaround for remount to handle the RO->RW change, but if the mount is using the new mount API, we do not do that, and rely on the mount tool NOT to set the ro flag. But that's not how the mount tool is doing for the new API: fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 <<<< Setting RO flag for super block fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 This means we will set the super block RO at the first mount. Later RW mount will not try to reconfigure the fs to RW because the mount tool is already using the new API. This totally breaks the per-subvolume RO/RW mount behavior. [FIX] Do not skip the reconfiguration even if using the new API. The old comments are just expecting any mount tool to properly skip the RO flag set even if we specify "ro", which is not the reality. Update the comments regarding the backward compatibility on the kernel level so it works with old and new mount utilities. CC: stable@vger.kernel.org # 6.8+ Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes") Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07riscv: defconfig: Enable T-HEAD C900 ACLINT SSWI driversInochi Amaoto
Add support for T-HEAD C900 ACLINT SSWI irqchip. Signed-off-by: Inochi Amaoto <inochiama@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241031060859.722258-4-inochiama@gmail.com
2024-11-07irqchip: Add T-HEAD C900 ACLINT SSWI driverInochi Amaoto
Add a driver for the T-HEAD C900 ACLINT SSWI device. This device allows the system with T-HEAD cpus to send ipi via fast device interface. Signed-off-by: Inochi Amaoto <inochiama@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241031060859.722258-3-inochiama@gmail.com
2024-11-07dt-bindings: interrupt-controller: Add T-HEAD C900 ACLINT SSWI deviceInochi Amaoto
Sophgo SG2044 has a new version of T-HEAD C920, which implement a fully featured T-HEAD ACLINT device. This ACLINT device contains a SSWI device to support fast S-mode IPI. Add necessary compatible string for the T-HEAD ACLINT SSWI device. Signed-off-by: Inochi Amaoto <inochiama@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/20241031060859.722258-2-inochiama@gmail.com Link: https://www.xrvm.com/product/xuantie/C920
2024-11-07irqchip/stm32mp-exti: Use of_property_present() for non-boolean propertiesRob Herring (Arm)
The use of of_property_read_bool() for non-boolean properties is deprecated in favor of of_property_present() when testing for property presence. Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Antonio Borneo <antonio.borneo@foss.st.com> Link: https://lore.kernel.org/all/20241104190836.278117-1-robh@kernel.org
2024-11-07irqchip/gic-v3: Force propagation of the active state with a read-backMarc Zyngier
Christoffer reports that on some implementations, writing to GICR_ISACTIVER0 (and similar GICD registers) can race badly with a guest issuing a deactivation of that interrupt via the system register interface. There are multiple reasons to this: - this uses an early write-acknoledgement memory type (nGnRE), meaning that the write may only have made it as far as some interconnect by the time the store is considered "done" - the GIC itself is allowed to buffer the write until it decides to take it into account (as long as it is in finite time) The effects are that the activation may not have taken effect by the time the kernel enters the guest, forcing an immediate exit, or that a guest deactivation occurs before the interrupt is active, doing nothing. In order to guarantee that the write to the ISACTIVER register has taken effect, read back from it, forcing the interconnect to propagate the write, and the GIC to process the write before returning the read. Reported-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241106084418.3794612-1-maz@kernel.org
2024-11-06Merge tag 'nfs-for-6.12-3' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client fixes from Anna Schumaker: "These are mostly fixes that came up during the nfs bakeathon the other week. Stable Fixes: - Fix KMSAN warning in decode_getfattr_attrs() Other Bugfixes: - Handle -ENOTCONN in xs_tcp_setup_socked() - NFSv3: only use NFS timeout for MOUNT when protocols are compatible - Fix attribute delegation behavior on exclusive create and a/mtime changes - Fix localio to cope with racing nfs_local_probe() - Avoid i_lock contention in fs_clear_invalid_mapping()" * tag 'nfs-for-6.12-3' of git://git.linux-nfs.org/projects/anna/linux-nfs: nfs: avoid i_lock contention in nfs_clear_invalid_mapping nfs_common: fix localio to cope with racing nfs_local_probe() NFS: Further fixes to attribute delegation a/mtime changes NFS: Fix attribute delegation behaviour on exclusive create nfs: Fix KMSAN warning in decode_getfattr_attrs() NFSv3: only use NFS timeout for MOUNT when protocols are compatible sunrpc: handle -ENOTCONN in xs_tcp_setup_socket()
2024-11-06media: dvbdev: fix the logic when DVB_DYNAMIC_MINORS is not setMauro Carvalho Chehab
When CONFIG_DVB_DYNAMIC_MINORS, ret is not initialized, and a semaphore is left at the wrong state, in case of errors. Make the code simpler and avoid mistakes by having just one error check logic used weather DVB_DYNAMIC_MINORS is used or not. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202410201717.ULWWdJv8-lkp@intel.com/ Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/9e067488d8935b8cf00959764a1fa5de85d65725.1730926254.git.mchehab+huawei@kernel.org
2024-11-06io_uring: avoid normal tw intermediate fallbackPavel Begunkov
When a DEFER_TASKRUN io_uring is terminating it requeues deferred task work items as normal tw, which can further fallback to kthread execution. Avoid this extra step and always push them to the fallback kthread. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d1cd472cec2230c66bd1c8d412a5833f0af75384.1730772720.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring/napi: add static napi tracking strategyOlivier Langlois
Add the static napi tracking strategy. That allows the user to manually manage the napi ids list for busy polling, and eliminate the overhead of dynamically updating the list from the fast path. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/96943de14968c35a5c599352259ad98f3c0770ba.1728828877.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring/napi: clean up __io_napi_do_busy_loopOlivier Langlois
__io_napi_do_busy_loop now requires to have loop_end in its parameters. This makes the code cleaner and also has the benefit of removing a branch since the only caller not passing NULL for loop_end_arg is also setting the value conditionally. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/d5b9bb91b1a08fff50525e1c18d7b4709b9ca100.1728828877.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring/napi: Use lock guardsOlivier Langlois
Convert napi locks to use the shiny new Scope-Based Resource Management machinery. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/2680ca47ee183cfdb89d1a40c84d349edeb620ab.1728828877.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-06io_uring/napi: improve __io_napi_addOlivier Langlois
1. move the sock->sk pointer validity test outside the function to avoid the function call overhead and to make the function more more reusable 2. change its name to __io_napi_add_id to be more precise about it is doing 3. return an error code to report errors Signed-off-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/d637fa3b437d753c0f4e44ff6a7b5bf2c2611270.1728828877.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>